JP2022088374A - Assembly for replacing tricuspid atrioventricular valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To describe developments which comprise in particular the use of a deformable region of the frame, various alternative embodiments of the sealing skirt, the use of a frame composed of multiple sub-sections, the use of fixing strands between the stent and the frame and of fixing elements for fixing the assembly to the native tissue, the use of sensors and/or actuators, and also the use of a stent in the inferior vena cava.

SOLUTION: An assembly for the tricuspid orifice of a human heart of the present invention comprises an external frame (100) connected to an internal stent (200) carrying a tricuspid valve bio-prosthesis (210) and a sealing skirt. The external frame is configured to hold its position in the native tricuspid annulus. The internal stent is connected to the external frame by one or more fixing strands. The sealing skirt covers the interstitial space existing between the external frame and the internal stent.

SELECTED DRAWING: Figure 4A

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to methods and systems for replacing defective atrioventricular heart valves or tricuspid valves.

The human heart has four heart valves. Two of these valves are called atrioventricular valves. The tricuspid valve is located between the right atrium and the right ventricle. The mitral valve is located between the left atrium and the left ventricle. The other two valves are located between the ventricles and the vascular system. The aortic valve separates the left ventricle from the aorta, and the pulmonary valve separates the right ventricle from the pulmonary artery.

In some medical situations, it may be appropriate to repair or replace the tricuspid valve. These medical indications are primarily due to the functional pathology of the tricuspid valve, which is difficult to identify, severe and can be associated with marked dilation of the tricuspid valve annulus. More rarely, this condition is due to rheumatic or infectious valvular disease, or even deterioration of the obstructed or leaking bioprosthesis.

Many systems have been shown to allow replacement of defective heart valves, especially by percutaneous or minimally invasive routes.

In particular, the technique of mitral valve replacement is known. In contrast, there is very little scholarly literature and strong supporting patent literature describing the orthotopic replacement of the tricuspid valve.

The published technical teachings about mitral valve replacement are, especially for physiological and pathological reasons (the anatomy of the tricuspid annulus is essentially only slightly fibrous and its size is large, It is oval. The anatomy of the right ventricle is also special.) It cannot be directly diverted in the case of tricuspid valve replacement.

The tricuspid valve is considerably larger than the mitral valve. In pathological situations, the tricuspid annulus swells to more than 40 mm in diameter, while the pathological mitral annulus is about 30-35 mm. This difference has several consequences, especially mechanical ones (eg, with respect to support, stability, and leakage around the prosthesis).

However, the opposite is generally conceivable. Procedures applicable to the tricuspid valve may be applicable to the mitral valve with strong grounds.

Although the patent literature reports documents claiming to be equivalent to both types of atrioventricular valves, in practice these technical teachings may generally apply only to the mitral valve.

U.S. Patent Application Publication No. 2014/0172707 and U.S. Pat. No. 8,657,872 are examples of such documents, and the technical teachings described therein apply to the replacement of the tricuspid valve. There are restrictions and / or drawbacks and / or deficiencies with respect to.

Although anatomically similar, the aortic and pulmonary valves actually require different procedures and / or replacement methods, given only in terms of their anatomical condition within the heart. It has characteristics.

In actual clinical practice, currently only the aortic valve is customarily replaced with a percutaneous valve. A bioprosthesis model of the percutaneous mitral valve is currently in the process of clinical evaluation. For the tricuspid valve, annuloplasty and annuloplasty (self-annuloplasty stenosis) are well known, but clinical procedures with a percutaneous orthotopic bioprosthesis are under development and are in the very early stages. It is in.

The present invention is included in the development of this latter.

In particular, there is a need for methods and systems suitable for tricuspid valve replacement.

U.S. Patent Application Publication No. 2014/01727070 U.S. Pat. No. 8,657,872

The present invention discloses a system for replacing the atrioventricular tricuspid valve. According to the present invention, the frame comprises a stent, which itself contains a tricuspid valve bioprosthesis. The diameter of the frame is therefore larger than the diameter of the stent carrying the bioprosthesis. In certain embodiments, the diameter of the frame is slightly larger than the diameter of the stent, and the stent itself is adapted to the diameter of the bioprosthesis.

The present invention also discloses a method for replacing the atrioventricular tricuspid valve. The route is generally a percutaneous transcatheter route. After a percutaneous approach, the system contained within the catheter is placed in place by the vascular route.

An assembly for the tricuspid valve ostium of the human heart, including an external frame connected to an internal stent carrying a tricuspid valve bioprosthesis and a sealing skirt, is disclosed, in which the external frame is (patient's). Can be placed in the heart and / or when placed in the patient's heart) is adapted to hold its position within the self-tricuspid valve annulus and has one or more internal stents. Connected to the outer frame by a fixed strand of, the sealing skirt (in packaged state and / or when placed in the patient's heart) provides the gap space that exists between the outer frame and the inner stent. Covering.

In one evolutionary form, the sealing skirt is self-organizing between the outer frame and the site of self-organization (ie, in some cases, i.e., folded or packaged) and / or the area of the annulus. It further covers the (contact) space that exists between the site (ie, in the context of being placed in the patient's heart).

In one embodiment, the sealing skirt creates creases or folds, both blocking the space in contact with the self-organization and covering the gap space between the frame and the stent upstream from the annulus. to enable.

In one embodiment, the skirt covers only this gap space and other means (eg, sealing bands or beads, biocompatible adhesives, or fillers, etc.) are used to prevent leakage around the prosthesis.

The frame is prestressed, or by its structure, exerts a radial force (radially outward), allowing the frame to be kept in place within its own annulus. The frame carries or contains a stent or is associated with a stent. The stent itself carries or contains a bioprosthesis or is associated with a bioprosthesis. The sealing skirt (by covering the "gap" space (still non-zero) that exists between the frame and the stent carrying the bioprosthesis with a diameter selected from a limited choice). Allows blood flow from the right atrium to the right ventricle through a bioprosthesis. The sealing skirt also covers and / or blocks and / or blocks (in the area of the annulus, the "contact" space existing between the outer frame pressed against the self-organization and the self-organization. This makes it possible to minimize (or even completely avoid) leakage around the prosthesis between the frame and self-organization. With a sealed skirt, blood flow is the entire width of the "contact" space. Blocked over (or stopped or blocked or blocked or prevented).

In one evolutionary form, the frame has a deformable region within the region corresponding to the self-valley.

In one evolution, the frame covered by the sealing skirt further has a shape upstream from the area of the self-valve to enhance the retention of the assembly within the self-valve.

This shape can be convex or flared to optimize blood flow capture, which contributes to the stability or maintenance of the assembly retention within the tricuspid valve annulus (by proper capture). Twisting of the assembly, ie, the mechanical effect of rotation / translation, which can be caused by blood flow due to the presence of the sealed skirt, is minimized).

In one evolutionary form, the frame further has a shape downstream from the area of the self-valve to minimize obstruction of blood flow.

In general, the portion of the frame that passes through the area of the right ventricle is dimensionally limited (see order below). In some embodiments, the function of the shape of this part of the frame can minimize turbulence (eg, special shapes, in particular, drag effects that tend to result in more laminar flow of blood. May be accompanied).

In one evolution, the frame contains multiple subsections.

In one embodiment, the frame is integral, i.e., integrally formed (eg, the frame is printed in 3D from a deformable material). In one embodiment, the frame comprises two subsections (eg, complementary or symmetrical). In one embodiment, the frame comprises three parts (in an economical and rugged arrangement configuration). In one embodiment, the frame comprises four subsections, a symmetrical arrangement configuration that is advantageous in terms of stability. In certain embodiments, the frame comprises a large number of subsections or frame wires.

In one embodiment, the different subsections of the frame are one with each other. In one embodiment, the different subsections of the frame are at least partially independent of each other. In some embodiments, at least one subsection of the frame is rigid, elastic, plastic, shape memory, heat sensitive, operable, instrumentable, configurable, and rebound. ) Has physical properties selected from the properties including.

In one evolution, the outer frame is connected to the inner stent by one or more strands.

In one evolution, the frame comprises four subsections, each of which is connected to an internal stent by a nitinol strand.

The configuration with 4 subsections and 4 strands makes the assembly particularly stable to the effects of mechanical twisting. Other embodiments include one or more "crossing" links between the sections of the frame and / or between the sections of the frame and the stent.

In one evolutionary form, the assembly further comprises at least one fixing element for fixing to self-organization.

Elements for anchoring to self-organization, in particular, improve the retention of the assembly during translation and / or rotation, closest to the area of the self-valley.

In one evolution, the placement of the sealing skirt may be configurable, reconfigurable or rearranged, for example, by an actuator.

For example, the spatial arrangement of the skirt can be adapted to the changes in space that exist between the stent with the bioprosthesis and the frame. The skirt can be actuated or rearranged to some extent, eg, remotely.

In one evolutionary form, the frame and / or stent and / or fixed strand and / or fixing element is made of a heat sensitive material and / or a shape memory material.

In one evolution, the assembly further comprises at least one sensor and / or marker.

The sensor can be, in particular, a position sensor, a motion sensor, a pressure sensor, or a chemical sensor and / or a biological sensor (biomarker). The marker can be, in particular, a radiation opaque marker.

In one evolution, the assembly further comprises an actuator suitable for modifying the structure of the assembly and / or adjusting the position of a portion of the assembly with respect to the self-valvele.

The assembly may be articulated or articulated. The rearrangement can be relative (relative to self-organization) and / or absolute (change in shape of the structure of the assembly itself). This reconstruction can be manual and / or automatic.

In one evolution, the assembly is connected to a stent suitable for placement within the inferior vena cava. The stent is connected to the frame of the assembly by a nitinol strand.

In one evolutionary form, the assembly is folded into a packaged state within a catheter for introduction by the percutaneous route (eg, by the vascular or transcardiac route).

A method of replacing the tricuspid valve is disclosed. The method comprises placing the assembly in a folded state within the catheter and introducing and indwelling the assembly by a percutaneous route.

Advantageously, the clearance space or gap (between a variable diameter frame and a standard size, i.e., gradual size, stent located within the frame) is of variable size.

Advantageously, the stent is secured to the frame (eg, on the atrial side) by, for example, one or more strands made of nitinol.

Advantageously, the shape of the frame includes three zones. One of these zones is located in the area of the self-valvele, the frame supports the self-cardiac tissue of the tricuspid valve annulus and its radial force holds the assembly in place.

Advantageously, according to some embodiments, the stent containing or supporting the bioprosthesis is placed asymmetrically with respect to the annulus (mainly in the atrium and in the right ventricle). It is rare).

Advantageously, entry into the right ventricle is minimized, in particular so as not to obstruct the flow of blood circulation.

Advantageously, some optional embodiments of the present invention include a system for maintaining a translational state (stent in the confluence of the inferior vena cava, which does not particularly obstruct blood flow, for fixation to self-tissue). There is one or more fixed elements).

Advantageously, various embodiments of the present invention allow for the placement of sealing skirts. The presence of this sealing skirt makes it possible, in particular, to minimize or prevent leakage around the prosthesis between the assembly and self-organization. The sealing skirt can be made of PET (polyethylene terephthalate) or another material that is impermeable to blood, covering the height of the annulus and covering the base of the frame on the atrial side.

Advantageously, embodiments of the present invention allow for facilitation of clinical practice and are associated with many proven or potential spillover effects (scale benefits, standardization of operation, improved safety, etc.). Valve bioprostheses currently on the market are usually "standardized", i.e., the range of various existing valves is limited and the valve dimensions are gradual (generally 35 mm, 40 mm and 45 mm). .. Customization (of the bioprosthesis) is possible, but it is costly and carries certain risks unique to the manufacture of non-standard prostheses. Embodiments of the present invention make it possible to eliminate the need to match the dimensions of the valve itself to the exact dimensions of the tricuspid valve annulus.

The dimensions of the frame on the one hand and the dimensions of the stent / bioprosthesis define the dimensions of the gap space (gap) that exists between the frame and the stent / bioprosthesis device. This space can be approximately a few millimeters in any case, depending on the configuration and / or requirements. For example, the diameter of the stent can be approximately 20% smaller than the diameter of the frame in the self-valve (in this configuration, the sealing skirt provides blood flow and eliminates leakage between the stent and the frame. Plays a central role in). In another case, the sealing skirt covers the space between the frame and the stent, allowing the diameter of the stent to be closer to the diameter of the frame in the self-valve.

There are several adjustment variables according to embodiments of the invention, in particular the diameter of the frame and the diameter of the stent carrying the bioprosthesis (diameter is measured in the self-valve). One of the adjustment variables is the shape and / or dimensions of the frame itself. The frame is actually a geometry (eg, bounce or loop or loop in the area of the annulus) that specifically allows further adjustment of the clearance space existing between the frame and the stent / bioprosthesis in the self-valve. May include edges or attachment points or anchors or undulations). Another adjusting variable is the diameter of the stent. Another adjusting variable is the diameter of the bioprosthesis itself.

Advantageously, the covering itself with a sealing skirt to fill the gap space can be optimized (eg, tension, creases or folds, skirts with various subsections, etc.). The sealing skirt between the stent / bioprosthesis and the frame provides specific elasticity (or tolerance), in particular, to allow the frame to accurately apply the morphology of the tricuspid valve annulus without stress. Can be maintained.

Other features and advantages of the present invention will become apparent from the following description and figures in the accompanying drawings.

FIG. 1A shows an example of a frame according to the present invention. FIG. 1B shows an example of an interconnect material for subsections of a frame. FIG. 2A shows a conventional stent. FIG. 2B shows a prior art tricuspid valve bioprosthesis. FIG. 3A is a diagram of the relative position of the frame with respect to the stent carrying the bioprosthesis. FIG. 3B shows a horizontal cross-sectional view at the height of the annulus region. FIG. 4A shows an example of an assembly according to the present invention. FIG. 4B shows a plan view of an example of the assembly according to the present invention. FIG. 5A shows another embodiment of the present invention. FIG. 5B shows the anatomical position of any fixed element. FIG. 6A shows the perimeter or clearance space between the stent and the frame. FIG. 6B shows another embodiment of the invention comprising a sealing skirt. FIG. 6B shows a cross-sectional view of an example of a sealed skirt at the height of the self-valley. FIG. 6C shows a horizontal cross-sectional view of an embodiment of an assembly comprising a frame, a stent carrying a bioprosthesis, and a sealed skirt. FIG. 7A shows another embodiment of the present invention. FIG. 7B is any embodiment that includes a stent placed in the inferior vena cava and connected to the assembly by a flexible link made of nitinol, with a radiodensity marker anchored to a frame in the right atrium. Is shown. FIG. 8 shows a method of placing the assembly according to the invention in place.

The tricuspid valve has certain features compared to the mitral valve, especially in terms of the actual structure (eg, geometry) and the environment in which it is placed (features are described in detail below).

In terms of geometry, the mitral and tricuspid valves are very different in their own right. The tricuspid valve chamber ostium provides communication between the right ventricle and the associated right atrium. The tricuspid valve atrioventricular ostium comprises an atrioventricular valve formed by three leaflets of different dimensions: anterior, septal and posterior. The mitral valve, on the other hand, consists of two valves or leaflets (anterior and posterior). The tricuspid valve is the largest of the four heart valves, and its surface area varies from 5 to 8 cm ² (while the surface area of the mitral valve is 4 to 6 cm ² ). The annulus of the tricuspid valve has a more elliptical or oval shape rather than a circular shape. Its fibrous structure is incomplete and is located in the shape of a horseshoe in a more robust septal region. In the case of tricuspid regurgitation, the less robust anterior (and partial, posterior) areas swell. Its diameter varies and is approximately 30-32 mm. The tricuspid valve has a perimeter of about 120 mm for men and about 105 mm for women. The tricuspid valve is formed by three elements: the valve web (three valve leaflets), the tricuspid valve annulus, and the subvalval apparatus (papillary muscle and chordae tendineae). ing. In contrast, the mitral valve has a diameter of 28 mm / m ² during diastole. The mitral valve is conical, with an annulus of approximately 30 mm and a valve apex (valve apex) of approximately 26 mm. The perimeter is 90 to 100 mm for women and 100 to 110 mm for men.

Moreover, in terms of geometry, the environment of the mitral and tricuspid valves is very different. In the right heart (consisting of the right atrium and the right ventricle), the right atrium is the confluence of venous blood containing CO ₂ from the two vena cava. The inferior vena cava has a diameter of about 30 mm (mm). The right atrium has more space than the left atrium and has a volume (or volume) of about 160 ml, while the left atrium has a volume of about 140 ml. The length of the right atrium is about 4.5 centimeters and the length of the left atrium is 3.5 centimeters. The structural aspects of the right and left ventricles are in contrast. The right ventricle has a thickness of 5-6 mm, while the left ventricle has a thickness of 12-14 mm. The average pressure in the right ventricle is 15 mmHg, while the average pressure in the left ventricle is 100 mmHg. Blood pressure is about 5 times higher in the left ventricle than in the right ventricle.

The pressure gradient between the right atrium and the right ventricle during diastole is less than 2 mmHg. The tricuspid valve corresponds to the atrioventricular ostium located in the circulatory system that functions at low pressure.

The right ventricle weighs about 70 g and the left ventricle weighs about 150 g. Therefore, the wall of the right ventricle is significantly more brittle than the wall of the left ventricle. If the bioprosthesis valve system is implanted between the right ventricle and the right ventricle, a relatively small anchoring means is provided on the side towards the right ventricle (the filling chamber of the right ventricle) and instead the atrium. It is advantageous to concentrate lateral fixation towards the right atrium (in terms of the mitral valve, the anchor is generally located under the mitral annulus on the side towards the left ventricle).

Therefore, these anatomical and physiological differences between the mitral and tricuspid valves (especially turbulence, blood flow recirculation regions, mechanical stress and force, material resistance and / or substitution) It involves significantly different mechanical or structural configurations (in terms of assembly stability, surgical replacement procedures, etc.). The present embodiment considers and utilizes these anatomical differences in the valve and the environment of the valve. This embodiment is particularly advantageous in terms of blood flow, resistance, stability, access, placement, and retention in place.

The drawings provided are for illustration purposes only. For example, the shape of the frame and the size of the gap space may be exaggerated for readability reasons to make the present invention easier to understand. In particular, the hook shape at the bottom of the frame is exaggerated. After all, it is only the function of the shape that is important, see the section detailing the intended function of the different parts of the frame.

FIG. 1A (the right atrium is labeled AD and the right ventricle is labeled VD) shows an example of a frame according to the present invention. In this example, the frame 100 includes a plurality of parts made of a metal alloy (eg, a heat-sensitive or shape memory alloy such as nickel-titanium alloy or nitinol).

Nitinol has a special function of changing its physical state by changing the temperature and has become the material of choice in the clinical field (Nitinol is frozen or packaged in a coolant and then 37. Maintains its final shape after being released into the bloodstream at ° C).

The frame is substantially cylindrical with three parts of different diameters, allowing the frame itself to be placed within the annulus of the tricuspid valve and to maintain its position within the annulus of the tricuspid valve. It allows and does not block blood flow through the tricuspid valve. In one embodiment, the frame comprises at least four elements (101, 102, 103, 104). The frame has an overall height of 32 mm to 45 mm (ie, adapted to the dimensions of the bioprosthesis). The bioprosthesis 110 is located within the frame.

The four main components of the frames 101, 102, 103 and 104 are interconnected in the narrowest annulus region by joints or flexible and deformable hinges. In one embodiment, the main component is made of nickel-titanium shape memory alloy. Each of the main parts is generally in the form of a capital letter S. The flexible and deformable hinge has a height of 5-7 mm and corresponds to the height of the annulus.

FIG. 1B shows an example of an interconnect material for subsections of a frame 100 according to an embodiment. In one embodiment, a (single) joining wire 110 connects various key components of the frame, for example, by welds. In one embodiment, the main components of the frame are connected by multiple joints or hinges (this latter embodiment makes the structure according to the invention more flexible). The embodiments of these hinges advantageously allow adaptation of the diameter of the frame considered as a whole by making this diameter variable and / or configurable. In another embodiment, the number of direct contact points is specifically adjusted (eg, increased) to increase the surface area in contact with the self-valve and to improve retention of the structure replacing the tricuspid valve. be able to. The example shown in FIG. 1B has 12 contact points. This type of configuration can advantageously reduce the risk of leakage around the prosthesis between the frame and the autologous tissue of the tricuspid valve annulus.

FIG. 1A shows that a frame according to an embodiment of the invention comprises three parts or regions. The direction of blood flow is indicated by arrow 199.

Within the region of the autologous heart valve annulus 131, the frame 100 is stretchable and / or deformable. Due to its radial force (eg, resulting from mechanical play of prestressed or four interconnected parts), the frame 100 is in the form of a tricuspid valve annulus (not completely circular, but elliptical). Often). The frame at the self-valve or its narrowest part is 40-42 mm. This diameter can reach 45 mm or even more than 50 mm for large dilations and corresponds to the anatomical region of the tricuspid annulus that defines the extent of the passage or opening between the right atrium and the right ventricle. The annular region (of the self-tricuspid valve annulus of the frame according to the invention) is 5-7 mm high.

In region 132 of the right ventricle, the frame continues downstream in the right ventricle in the direction of blood flow. In one embodiment, the frame extends in the right ventricle over a height of 10-12 mm and extends on the right ventricular side (ie, has a convex shape). The maximum diameter 1321 of the portion of the right ventricle is slightly larger than the diameter in the area of the annulus. In its distal portion of the right ventricle, the ends of the frame terminate at a diameter (eg, 35 mm or 40 mm) having a value substantially equal to the diameter of the bioprosthesis. This mechanical configuration (ie, the choice of convex shape and diameter) advantageously allows the three leaflets forming the self-tricuspid valve to remain open, allowing the filling chamber of the right ventricle to remain open. Does not cause obstruction of blood flow (no obstruction of the right ventricular outflow tract).

Located in the region 133 within the right atrium, upstream from the region of the annulus, is the proximal portion of the frame located in the right atrium. In one embodiment, the frame has a convexly flared shape. In one embodiment, the maximum diameter 1332 is 6-8 mm larger than the diameter of the annulus region. For example, if the annulus is 42 mm, the diameter value can be 50 mm. In this region 133 within the right atrium, the frame extends over variable distances depending on the dimensions of the bioprosthesis. For example, this distance can be approximately 15 mm. This area of the frame in the right atrium corresponds to the area of attachment to the stent containing the bioprosthesis.

FIG. 2A shows a conventional stent 200. In one embodiment of the invention, the stent 200 used is a self-expanding stent. The stent 200 is cylindrical and is formed of a plurality of cells 201 of a metal alloy, for example, the same alloy (titanium-nickel) as the alloy of the frame 100. The diameter of the stent 200 can be slightly smaller than the diameter of the frame in the area of the annulus. The dimensions of the stent 200 are generally gradual and the standard dimensions are 30, 35, and 40 mm. The dimensions of the stent correspond to the dimensions of the bioprosthesis 210 (the stent 200 carries the bioprosthesis 210).

FIG. 2B shows a prior art tricuspid valve bioprosthesis 210. The tricuspid valve bioprosthesis is formed of three valve leaflets (211,212, 213) made of animal tissue (eg, bovine or porcine pericardium) and / or synthetic fibers. The three valvular apex or "valve apex" forming the bioprosthesis are connected (eg, associated or fixed) within or on the stent or by the stent or via the stent. Attached or welded or sewn). The bioprosthesis functions in the physiological direction of blood flow, reaches the right atrium, and is introduced into the filling chamber of the right ventricle during systole.

Various techniques can be used to connect stents and bioprostheses to different contact points 220 (eg, welded, glued, fixed links or springs, flexible or partially rotating contact points, etc.). In one embodiment, three contact points 220 are used to allow for more secure fixation of the tricuspid valve. In one embodiment, the bioprosthesis is held within the stent by multiple contact points (4 or more). The probability of breakage generally decreases as the number of contact points increases.

FIG. 3A is a diagram of the relative position of the frame 100 with respect to the stent 200 carrying the bioprosthesis 210. In one embodiment, the stent containing the bioprosthesis is located within the frame. The proximal end 301 (ie, the base) of the stent is located in the right atrium region 133 of the frame. The bioprosthesis 210 is therefore primarily in the infra-annulus position. The distal end of the stent 302 containing the bioprosthesis 210 is located within the region 132 of the right ventricle, albeit only a few millimeters. The stent is therefore placed asymmetrically with respect to the region of the annulus, which is the narrowest part of the frame.

FIG. 3B shows a horizontal cross-sectional view at the height of the annulus region. This figure shows the presence of frame 100, stent 200, and bioprosthesis 210.

FIG. 4A shows an example of an assembly according to the present invention.

The frame 100 is connected to the stent 200, including the prosthesis 210, by one or more strands.

The number, location, and properties (eg, material) of the strands will vary depending on the embodiment (assembly is more flexible or less flexible, more stable or maintained or less stable. Or less maintained, more disturbing or less disturbing circulation, etc.).

In certain embodiments, a single fixed strand may be sufficient (the transfer of mechanical force through this optionally enhanced single strand can be modeled and optimized). Advantageously, the obstruction of blood flow is minimal.

A configuration with two or three strands is possible.

In the example shown in the figure, the stent is held in the frame by four strands 411,421,413,414.

In one embodiment, the stent 200 is attached to the base of the frame 100 (in its region 132 in the right atrium) by the four strands of the example shown in the figure (in its widest region, i.e., region 132 in the right atrium). is doing. This configuration, which is attached upstream of the circulation of bloodstream, has the advantage of providing torsional stability of the stent downstream. According to one embodiment (not shown), in addition to or instead of attachment by the upstream side of the valve and the base of the stent, one or more additional, optional attachments of the stent to the frame of the annulus. It can be done in the region or through the distal portion of the stent (even if the distal portion of the stent is slightly within the right ventricular region).

In one embodiment, the one or more strands (or "tabs") are made from nitinol. In general, thermal and / or shape memory materials may be used.

In one embodiment, the one or more strands are rigid. In some embodiments, the one or more strands are elastic or flexible or deformable. Other embodiments combine elastic and rigid strands (eg, depending on the dynamic behavior of the structure of the assembly). Other high performance embodiments involve the use of operable or configurable strands.

FIG. 4B shows a plan view of an example of the assembly according to the present invention. This figure specifically shows the placement of the bioprosthesis 210 within the frame 100.

FIG. 5A shows another embodiment of the present invention. The assembly has one or more optional fixing elements (ie, for holding in the heart). In one embodiment, the fixed element has the form of a "racket" or "loop" or "tab" (eg, reference number 501). In one embodiment, the fixing element is made of a nitinol alloy. The fixing element has a height of approximately 8-10 mm and a length of 10-12 mm. In one embodiment, one or more of these arbitrary fixing elements are joined to the frame 100 in the annulus region 131 and are open only on the atrial side. In some embodiments of the invention, no fixing element is used. In one embodiment of the invention, a single fixed element is used. In one embodiment of the invention, the two fixed elements are symmetrically arranged. For improved stability, a second fixation element can actually be placed (eg, symmetrically towards the atrial septum). However, this form may increase the risk of electrical conduction impairment (including atrioventricular block) in some cases. In one embodiment, multiple fixation elements are used to reduce the risk of conduction failure.

The technical effect (function) of such a mounting element is, in particular, to stabilize and secure the frame 100 in the heart. In particular, these fixing elements improve the stability of the assembly according to the invention during rotation and / or twisting and / or translation.

FIG. 5B shows the anatomical position of any fixed element. A retention loop is located upstream of blood flow 199. In the embodiment shown in FIG. 5B, the assembly comprises two fixing elements 501 and 502. These elements are arranged symmetrically with respect to the frame. Each element is placed substantially perpendicular to the frame and supports the wall of self-organization. One of the fixation elements 501 is located on the side of the atrial septum, and the other fixation element 502 is located on the outer wall of the right atrium (called the pectinate muscle). According to embodiments, there are various techniques used to attach the fixing element to the frame. For example, the mounting location can be welded. From a dynamic point of view, multiple fixation elements are spontaneously or automatically placed outward during the release of the frame during removal of the catheter that delivers the entire system.

FIG. 6A shows the perimeter or clearance space between the stent and the frame. In fact, there are various sizes of free perimeter space 601 between the stent 200 and the frame 100 in the area of the self-valve. The function of the frame 100 is, in particular, to maintain and stiffen the entire system while applying radial forces to the self-valve, ensuring a stable placement within the heart. Stents and bioprostheses are cylindrical (gradual and standard sized). The diameter of the stent and the diameter of the bioprosthesis are substantially equal and smaller than the diameter of the frame. Therefore, there is a gap space (gap) between the frame 100 and the stent 200.

FIG. 6B shows another embodiment of the invention comprising a sealing skirt (cross-sectional view).

Many alternative embodiments are possible for the location and nature of this sealing skirt.

The function of the sealing skirt is to seal the assembly according to the invention (ie, the system formed by the frame and the stent carrying the bioprosthesis) (especially in the area of the atrioventricular annulus). In particular, the sealing skirt minimizes the risk of leakage around the prosthesis (hereinafter Article 6104).

The sealing skirt 610 totally supports the frame and at least partially covers the stent 200.

In one embodiment, the attachment start point 6101 of the sealing skirt 610 is sewn (or coupled) to the outer wall of the stent over a height that broadly covers the area of the annulus. The fabric of the sealing skirt is then folded (eg, folded 180 ° outward) and descends along the inner wall of the frame 6102. Finally, by its intracardiac base, the fabric of the sealing skirt surrounds the frame 100 by raising the outer wall of the frame 6103 and is sewn or sewn to the capital S-shaped joints and / or elements of the frame 100. By terminating above the area of the bonded annulus, this frame is reinforced in the narrowest area pressed against the self-organization 6104. This point 6104 plays a crucial role in preventing leaks around the prosthesis, in particular. In another embodiment, the sealing skirt does not have to completely cover the frame.

In one embodiment, the encapsulating skirt is made of a synthetic material (eg, polyethylene terephthalate or PET, a flexible material that is impermeable to water or blood). In one embodiment, a sealing material such as Dacron may be advantageously used. The skirt may contain, for example, multiple materials arranged in layers and / or sections (ie, eg, atrial side, upstream from the annulus region to minimize the thickness of the assembly during packaging. On the side, it comprises an area containing a reinforced area and / or a single layer and / or an openworked space ("opening", "hole", porous or permeable subsection, etc.)).

The structure of the skirt (eg, materials, subsection arrangements, layers, distribution of openworked spaces, etc.) is particularly optimized (ie, to minimize the thickness of the assembly during packaging). And / or to ensure resistance to blood flow in the skirt thus constructed and / or to contribute to enhanced retention of the assembly in place (eg, stability during rotation and / or translation). As) can be carried out.

From the upstream side to the downstream side and from the right atrium to the right ventricle, the assembly according to the present invention slightly modifies blood flow. On the upstream and atrial sides, the convex structure of the frame is accompanied by some turbulence of blood flow, but this change is not acceptable or medically or mechanically significant. The patient is under treatment with an anticoagulant to prevent clot formation due to the presence of the bioprosthesis and its frame. As a result, the rheology of blood changes.

In Zone I (“contact” region or space) of FIG. 6B, blood flow is “blocked” (or stopped or blocked or blocked or prevented) or in the region of the self-valve (ie, the entire perimeter and at least partially). It is at least substantially minimized over the height of the corresponding cylinder of the heart valve annulus.

In Zone II (“gap” region or space) of FIG. 6B, a skirt captures blood flow and sends it through a bioprosthesis for its leakage resistance. The shape of crease 6110 (FIG. 6B) can accidentally affect recirculation in the direction of the bioprosthesis. Some advantageous embodiments involve more or less "tightening" or "relaxing" this fold of the skirt to optimize the dynamic flow of blood flow. Since the diameter of the bioprosthesis is actually only slightly smaller than the diameter of the autologous annulus, there is a slight obstruction of blood flow around the perimeter of the valve itself. However, since the autologous annulus is dilated by a medical condition that justifies the replacement of the tricuspid valve, this particular inhibition is negligible as a percentage. In the area of the annulus, the frame is applied (in contact) to the self-organization. Leakage between the frame and the self-tissue is not really present or slight (ie, due to the absence of tricuspid annulus calcification that does not allow the formation of a gap space between the frame and the self-tissue). , And also because the fabric of the skirt forms creases in the area of the annulus to improve leak resistance in this area). The prosthesis system is sealed with three times the thickness (of the material (eg, of PET)), favorably eliminating leaks beyond the prosthesis between the prosthesis and the self-organization, but of the assembly. The thickness may increase in its folded configuration. Another embodiment makes it possible to meet these requirements by moving the folding area or arranging the various components of the assembly to optimize its geometric folding.

Some embodiments of the invention provide the use of strands and / or stent meshes having a tubular or cylindrical or elliptical shape to minimize their effect on red blood cells. In one embodiment, the cross section of the strand and / or stent mesh is elliptical to improve rheology and / or to optimize local and / or global blood flow (of "aircraft flaps"). (Like) is oriented. Finally, from the ventricle side to the downstream side, the flow is partially delivered by the stent and does not cause any medical side effects (particularly this does not result in obstruction of blood flow into the right ventricle). The frame is wider (convex outward) on the downstream side of the annulus, but smaller in diameter than the upstream region and does not interfere with the approximately 10 mm ejection path to the pulmonary valve located in the right ventricle.

FIG. 7A shows a completely arbitrary alternative embodiment of the invention, including further fixation to a stent placed in the inferior vena cava.

In some rare anatomical situations, the (often dilated) tricuspid annulus may not have a stable mounting or calcified area. In these particular cases, it is advantageous to place specific, additional, arbitrary fixed devices in place, and by combining these with the assembly according to the invention, the assembly according to the invention (eg, when translated). ) Improves retention and maintenance.

According to this another embodiment, a self-expandable stent 701 (eg, made of Nitinol) is placed in the inferior vena cava at a distance from the frame. The stent 701 has a variable diameter of approximately 30 mm and is adapted to the size of the confluence of the inferior vena cava to its right atrium. The stent placed in the inferior vena cava should be shorter than the additional fixation means provided in the mitral valve so as not to interfere with the circulation of the suprahepatic vein. In other words, the arrangement of the fixing means in the case of the tricuspid valve is also special compared to the arrangement of the mitral valve. The stent 701 is connected to the frame 100 in various ways (eg, by wire link 702). The wire link 702 is connected to the stent 701 at the confluence of the inferior vena cava and above the stent 701 flush with it. The lower portion of the wire link 702 is connected to the main frame at the base of the right atrium. The wire link 702 can be visualized by a radiodensity marker in fluoroscopy. This flexible and deformable wire link can be straight or wavy. Its length can be adapted (plus or minus 30 mm depending on the anatomical distance between the tricuspid annulus and the inferior vena cava).

FIG. 8 shows a method of arranging a system or assembly according to the present invention. In a first state, referred to as "folded" or "compressed" or "packaged", the delivery catheter 800 (or "delivery system") is a frame, a stent, a bioprosthesis, (and also). , As appropriate, including a fixing element according to another embodiment, and a sealing skirt). In a second state called "relaxed" or "released" or "uncompressed", the assembly according to the invention is placed in the patient's heart (by operation on the part of the operator).

In one embodiment of the invention, in the packaged state, the bioprosthesis is "folded" within the stent and the stent itself is "folded" within the frame (with the encapsulating skirt).

Hereinafter, different embodiments of "release" of the assembly according to the present invention will be described. The instrument and release device or "delivery system" a) has an appropriate length (approximately 280 mm) adapted so that its non-traumatic distal end is curved in a "curly shell shape" and placed within the right ventricular cavity. A 0.35 inch guide (length) and a catheter (formed by a coaxial tube) having a length adapted to the distance of the total femoral vein (in the inguinal medial space) to the right atrium and right ventricle. This catheter or sheath, called an over-the-wire catheter, is centered around a 0.35 inch guide. The catheter has a retractable sheath at its distal portion, the diameter of which is 18-24 Veins in the assembly according to the invention. Is suitable. At its distal end, the sheath is a non-traumatic conical tip adapted to accept a 0.35 coaxial guide that is adapted to traverse the tricuspid valve and be located at the tip of the right ventricle. Part precedes.) C) Includes a handle, including a mechanism for releasing the bioprosthesis. This handle is welded to a coaxial tube. The handle controls the indwelling of the assembly. The handle has a knurled screw that controls the placement and release of the assembly. The device is also provided with a system for bending and guiding the tube at its distal end prior to the sheath containing the assembly according to the invention.

Hereinafter, a method for indwelling and releasing the assembly according to the present invention will be described. The sheath (18-24 Fr) is retractable and accommodates the assembly according to the invention (due to its possible variants). In the first step, a 24Fr digital that is adapted to accept the introducer system is percutaneously placed in place in the total femoral vein. In the second step, a 0.35 guide is placed at the tip of the right ventricle. In the third step, the introducer system containing the frame and bioprosthesis is inserted into the Digilet and then pushed through the inferior vena cava on a 0.35 guide to the right atrium. In the fourth step, upon reaching the right atrium, a mechanical handle bends the sheath at its end towards the tricuspid valve opening. In the fifth step, the assembly is then pushed over the tricuspid valve. In a sixth step, the frame is gradually indwelled under fluoroscopy (radiation impermeable markers are placed at the height of the annulus region of the frame) and transesophageal echocardiography and / or 3D control. To. A knurled screw on the handle that rotates clockwise gradually releases the frame containing the bioprosthesis under transesophageal echocardiography and fluoroscopy. In a seventh step, after the area of the annulus, one or more fixation elements (“hooks”, “rackets”” that continue to be indwelled and pressed against the outer wall of the atrium and atrial septum in a portion of the right atrium. , "Loop") is released. At the same time, the bioprosthesis is released and begins to function as soon as part of the frame in the right atrium is completely released. In any step corresponding to one embodiment, including placement of a fixed stent in the inferior vena cava, the sheath is continuously removed into the anastomosis orifice and framed by a nitinol strand. Release the immobilized stent. This is done under transesophageal echocardiography and fluoroscopy, accompanied by a radiodensity contrast medium. Finally, angiography and transesophageal echocardiography are performed to ensure that the bioprosthesis in place within the autologous tricuspid valve is leak tolerant, ie, leak free.

In some embodiments of the invention, the assembly may include a sensor (eg, an active sensor of one or more passive markers) and / or an actuator.

The assembly according to the invention may include, in particular, a radiation opaque marker for quantifying, measuring, and confirming the correct position of the assembly in the patient's heart.

In addition or / or the assembly according to the invention may also include a device that allows movement or spatial readjustment of the assembly. The position of the assembly may change or even change over time.

In other words, the assembly according to the invention may be static in some embodiments and / or dynamic or adaptive in other embodiments. The assembly according to the invention may particularly include one or more microelectromechanical systems. A microelectromechanical system is a micrometer-sized microsystem containing one or more mechanical elements that use electricity as an energy source to realize sensor and / or actuator functions. In another embodiment, a biomedical microelectromechanical system is used. Actuators may be placed in or on different parts of the frame and / or in the mounting area of different subsections of the frame and / or in or on the strands that mount the frame to the stent.

The actuator in particular, for example, to reconstruct the shape of the frame (eg, its convex surface) and / or to adjust the coating provided by the sealing skirt (eg, the curvature of the skirt surface at a particular location). , Folding, tension, etc.), and / or can be used to adjust the fixation of the stent to the frame. Movement or spatial readjustment is generally performed over short distances. Movement or spatial readjustment can be reversible or irreversible (eg, mechanical stoppage). Movement or spatial readjustment may be configurable and / or configurable. Movement or spatial readjustment can be determined, at least in part, by an external device, i.e., in open loop (can be controlled by the operating physician). Spatial changes can be fixed by logical and / or physical devices where appropriate. Structural changes made to the structure can also be controlled, for example, in a closed loop according to the static position and dynamic behavior measurements of the assembly inserted into the bloodstream.

In one embodiment, the assembly of the invention is modified to allow replacement of the mitral valve. The terms "tricuspid valve" and "mitral valve" are generally not interchangeable. In one particular embodiment of the invention, the assembly allows for mitral valve replacement, taking into account that the diameter of the pathological mitral valve is significantly smaller than the diameter of the pathological tricuspid valve. Will be modified. Among the static modifications, among others, when compared to the tricuspid valve assembly, in addition to the mitral valve bioprosthesis, there are fewer subsections that make up the frame (eg, mechanical stability that can be more easily obtained). Degree), and if possible, priority is given to using a smaller value of sealing skirt thickness in the packaged state.

Claims (14)

An assembly for the tricuspid valve of the right heart of the human heart
An external frame (100) connected to an internal stent (200) carrying a tricuspid valve bioprosthesis (210) and a sealing skirt (610).
Including
The outer frame (100) is configured to hold its position within the self-tricuspid valve annulus.
The internal stent (200) is connected to the external frame by one or more fixed strands.
The sealing skirt (610) covers the gap space existing between the outer frame (100) and the internal stent (200).
The sealing skirt (610) is configured to block the contact space between the outer frame (100) and a site of self-tissue within the region of the self-tricuspid valve annulus.
Assembly. The assembly of claim 1, wherein the outer frame (100) has a deformable region configured to hold the assembly in place within the self-tricuspid valve annulus. The outer frame (100) has a shape configured upstream from the region of the self-valve ring to enhance retention of the assembly within the self-tricuspid valve annulus, claim 1 or 2. The assembly described in. The outer frame (100) has a shape downstream from the region of the self-valve ring so as to enhance the holding of the assembly in the self-tricuspid valve annulus. The assembly according to any one of the above. The assembly according to any one of claims 1 to 4, wherein the outer frame (100) is connected to the internal stent (200) by one or more strands (411,421,413,414). .. 15. The outer frame (100) comprises four subsections (101, 102, 103, 104), each of which is connected to the internal stent by a nitinol strand, according to claim 5. Assembly. The assembly according to any one of claims 1 to 6, further comprising at least one fixing element (501, 502) for fixing to the self-organization. The assembly of any one of claims 1-7, wherein the sealing skirt (610) comprises several subsections and / or some material layers. Claims that the frame (100) and / or the stent (200) and / or the fixed strand (411,421,413,414) and / or the fixed element (501,502) include a heat sensitive material and / or a shape memory material. The assembly according to any one of Items 1 to 7. The assembly according to any one of claims 1 to 9, further comprising at least one sensor and / or a radiodensity marker. Any one of claims 1-10, further comprising an actuator suitable for modifying the structure of the assembly and / or suitable for adjusting the position of a portion of the assembly with respect to the self-valley. The assembly described in. The assembly is connected to a stent (701) suitable for placement in the inferior vena cava, which is connected to the frame of the assembly by a strand made of nitinol, claim 1. The assembly according to any one of 11 to 11. The assembly according to any one of claims 1 to 12, wherein the assembly is folded into a state (800) packaged in a catheter for introduction by a percutaneous route. A method of replacing the tricuspid valve, wherein the assembly according to any one of claims 1 to 13 is placed in a folded state in a catheter, and the assembly is introduced by a percutaneous route. And the step to detain,
Including, how.

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